Geochemical Features and Significance of Dioritoid and Granitoid Rocks in Eji’naqi and Its Neighboring Areas
详细信息
- 责任者：Jing Guoqiang (College of Earth Sciences and Resources Management ; Chang’an University ; Xi’an 710054 ; China) ; Dang Ben
- 刊名：Mineral Resources and Geology
- 出版年：2011
- 卷期：25(4)
- 关键词：闪长岩 ; diorites ; 花岗岩类 ; granitoid ; 岩石地球化学 ; lithogeochemistry ; 内蒙古 ; Inner Mongolia
- 页码：p.302-310
- 图表：illus., 3 tables, 15 refs.
- 分类号：0801
- issnNo：ISSN1001-5663
- isbnNo：CN45-1174/TD
摘要
Geochemistry of granitoid rocks in Eji’naqi and four neighboring areas was analyzed and discussed so as to better understand its lithology and rock geochemistery characteristics,as well as its tectonic significance.Their rock types are mainly dioritoid and granitoid rocks.Content of SiO2 ranges from 47.88% to 75.29% and Al2O3 from 13.09% to 17.49%.The CIPW report shows that most samples belong to series saturated with aluminium and excessive SiO2,and are rich in aluminium、natrium and kalium.All these characteristics suggest that it belongs to series of peraluminous rocks.The REE original mantel standard cobweb diagram shows that these four areas are slightly different in modalities,with Yagan showing negative Sr abnormity,while other three areas shows obvious negative Ta、Nb abnormity.The REE diagram shows slow rightward incline and relatively rich in light REE and poor in heavy REE,and some samples in Yagan、Pengboshan and Yabulai areas show negative Eu abnormity.In the research area,the neutral and acidic intrusive rocks are mainly type I,according to Chapppell et al.,and diagenetic material is probably partially melt newly formed crust owing to dynamics of collisional orogeny.The types of strongly peraluminous rocks are probably resulted in rising and emplacement of partially melt magama,which is crust source compressional environment genesis.In the R1-R2 tectonic setting distinguish diagram,samples in Yingen area are within the bounds of synchronized collisional deep melted granite,those in the Yagan area are within the bounds of rising deep formed rockbody after collision,while those in the Pengboshan area are all on the verge of destroyed plate before they collide,which shows that these three areas have obvious different genesis.